Mounting OB swim platform support-gctid650285

05-20-2015, 09:13 AM

I'm looking to add a small swim platform (really just a platform for putting a ski on - no rail, no ladder - just a 12" long x 13" wide platform extending off the molded-in step/platform on my little Capri 160). I'd like to run a diagonal support pole down from the rear edge of the platform extension to the transom. The gas tank is on that side of the boat, so I have no access to the transom in that area for through-bolting. ( I believe there is also a floor below the gas tank, judging from the other side of the boat, where the battery sits.) Tapping around on the transom in that area, it sounds hollow down about 2-3" of the bottom edge, then it seems to be solid. I have no idea if that's solid glass, if there's wood running along the bottom, if its questionably solid (in terms of FG) behind there, or what.

I'd just like to confirm w/ someone who might know more about the structure in that area, that it'd be reasonably safe to put a healthy-sized screw (#12 or #14 x 1") into that area, and if so, how close/far from the bottom edge would be best to put it. The pole would be stainless, with a welded tab on it, which is what would be screwed to the transom. It would be bolted to the rear edge of the platform extension. (The platform extension itself would actually sit on top of the molded-in platform, and would be through bolted to the deck/platform with an alu backing plate beneath, FWIW.)

Jim, it's always hard to advise when it's sight unseen. I also must admit to little knowledge about the construction of that particular model. That being said, is the support tab (sounds like a U type channel swing tab with a pin holding the pole to the tab) capable of having two screws vs one, preferably one above the other. IMHO, a single screw can work loose, placing torsion movement on the tab with potential water egress into the screw hole.

In the past I have done what you describe on my old inboard ski boat about an 1 1/4" above the bottom edge. From what you describe, it sounds solid, but you should ensure the screw thread/hole has plenty of sealant while screwing it in. A small pilot hole will provide the answer, then a larger appropriate hole for your actual screw. I presume you're using large pan head s/s screws.